Trying to play this on Ubuntu as I'm having a major issue with Windows 7 and my PC (there's nothing wrong with my PC JSYK, it's an activation issue because I was sold an OEM version of Windows 7 instead of a retail one..). Anyway, on Windows 7 I get a super smooth 60 FPS with the game maxed, on Ubuntu it stutters like a ♥♥♥♥♥ on the lowest and highest settings. It kinda keeps dropping the FPS majorly every 3/4 seconds, and is completely unplayable. Any idea how to fix it? :/

I'm almost certain it isn't using the A8 APU. You have to plug into the motherboards HDMI port or VGA to get the APU graphics to work. The HDMI is plugged into the Radeon 7850. Also, as you can see from the screenshot, the Catalyst Control Center only lists the Radeon 7850.